Method of and apparatus for handling frisketing material



Se t. 9, 1958 w. P. CRAWFORD 2,850,972

METHOD OF AND APPARATUS FOR HANDLING FRISKETING MATERIAL Filed March 15, 1957 2 Sheets-Sheet 1 All" O O O 1958 w. P. CRAWFORD 2,850,972-

METHOD OF AND APPARATUS FOR HANDLING FRISKE TING MATERIAL 2 Sheets-Sheet 2 Filed March 15, 1957 ice Patented Sept. 9, 1958 METHOD OF AND APPARATUS FOR HANDLING FRISKETIN G MATERIAL Wayne P. Crawford, Hamilton, Ohio Application March 15, 1957, Serial No. 646,309 Claims. (Cl. 101-421) This invention relates to new and useful improvements in the art of engraving and printing, and in particular the invention concerns itself with the handling of frisketing material used for frisketing or blanking out of so-called dead metal spots or areas on a master plate when prints are taken therefrom to furnish engravers proofs.

In accordance with conventional practice, after a Inaster plate is inked preparatory to the making of a print, the dead metal spots are individually covered with pieces of frisket paper which are placed in position with the aid of tweezers, or the like, and prevent the dead metal spots from printing when a print from the plate is made. However, before a second print can be made, it is necessary to re-ink the plate, which requires removal of the pieces of frisket paper so that they do not become coated with ink. After inking, the individual pieces of frisket paper must again be applied to the plate, preparatory to printing. This removal and replacement of the pieces of frisket paper therefore must be repeated for each individual print, and inasmuch as several dozen prints are usually taken and inasmuch as several individual pieces of frisket paper are commonly required for a plate, it is obvious that the repeated removal and replacement thereof is a tedious and a very expensive task.

An effort has been made to eliminate this difficulty by grinding or routing away the dead spots in the plate, but the material thus removed must be replaced subsequently by a substitute in order that the master plate may be used for making of satisfactory electros or duplicates. In other words, without the dead metal spots to protect the master plate, the making of electros would damage the same, and accordingly, it becomes necessary to replace the routed away material by a substitute, such as for example, a filler of plastic. This procedure, however, involves not only a loss of time and effort in removing the dead metal spots and subsequently replacing them 1 with the plastic substitute, but what is more damaging,

the heat and pressure used in making a mold from the master plate has a tendency to soften the plastic filler and press it below the high printing surface of the plate.

The present invention eliminates all of the foregoing disadvantages by the provision of a process and apparatus whereby the several individual pieces of frisketing material, once applied to the dead metal spots of the plate after inking and preparatory to printing, may be simultaneou'sly removed from the plate after taking of a print, so that the plate may be re-inked; whereupon the several pieces of frisketing material may be simultaneously redeposited on the plate with'positive accuracy so that they cover the respective dead metal spots from which they were removed.

The principal object of the invention, therefore, is to provide an improved process or method for handling the frisketing material in the manner above outlined, while another object of the invention is to provide an apparatus whereby such handling may be effected.

In accordance with the invention, the customary frisket paper used for covering thedead metal spots is substituted by material which responds to magnetic forces, such as for example, thin metal or shim stock. Then, electr'o-magnetic means areprovide'd for bodily picking up such frisketing material from the 'plate,-holding the same in a fixed position while the plate is beinginked, and redepositing the same on the plate after inking, in the exact spots from which the frisketing material was removed.

As such, the invention completely eliminates the conventional need for repeatedly removing and replacing the individual pieces of frisketing material for the making of successive prints, and the time and labor saving features of the invention become readily apparent.

With the foregoing more important objects and features in view and such other objects and features as may become apparent as this specification proceeds, the invention will be understood from the following description taken in conjunction withthe accompanying drawings, wherein like characters of reference are used to designate like parts, and wherein:

Figure 1 is a side 'elevational view of the invention positioned on a printing press, only a portion of the latter being shown;

Figure 2 is a top plan view thereof;

Figure 3 is a fragmentary sectional detail, on an enlarged scale, taken substantially in the plane of the line 33 in Fig. 2;

Figure 4 is a sectional detail, on an enlarged scale, taken substantially in the plane of the line 4-4 in Fig. 2;

Figure 5 is a perspective view of one of the magnets and its supporting means;

Figure 6 is a top plan 'view of the magnet and its supporting strap;

mean for the magnets;

Figure 9 is a wiring diagram of the electrical components used in the invention; and

Figure 10 is an underside .plan view of an engraved master plate with which the invention may be used.

Referring now to the accompanying drawings in detail, Figure 10 illustrates an engravedmaster plate carrying, for example, the word Cool, the plate being designated by the reference numeral 11 and the letters forming the word being shown at 12. Portions 13 of the plate surrounding the letters 12 are relieved or undercut to facilitate formation of the letters, while the shaded areas 14, 15 of the plate are areas 'or'spots of dead metal.

When engravers proofs are to be printed from the master plate 11, the plate is inked and pieces of frisketing material are applied to the areas 14, 15 to prevent the same from printing when a print is made. A single piece of such frisketing material is usually'sufficient to cover the area 14 outside of the relieved portions 13, but individual pieces of frisketing materialmust be applied to the areas 15 which are isolated inside the spaces 13, as will be clearly apparent. The plate -11 may contain a dozen or more isolated areas such'as those shown at 15, and since the frisketing material applied to such areas must be re moved to facilitate re-inking of the plate before each print is made, the matter of removing and subsequently replacing suchindividual pieces of frisket material is a tedious and an expensive procedure.

In accordance with the invention, all pieces of frisket material applied to the several areas 15 are removed simultaneously, held in a fixed position upon removal to permit inkingof the plate, and finally replaced with accuracy to the respective dead metal spots (15) from which they were removed, so that the matter of handling such individual pieces of frisket materialis substantially simplified and expedited.

The apparatus whereby the frisket material handling process under the invention is carried out comprises a substantially rectangular frame 16, provided at the corners thereof with legs 17, so that it may be positioned on a suitable support, such as a printing press 18 on which the engraved plate 11 is disposed in an inverted position. Suitable hinges 19 are provided at the back of the frame 16 for attaching the latter to the press 18, it being noted that by virtue of these hinges the frame may be swung upwardly and away from the press, as indicated at 20. The hinges 19 are secured to the frame and to the press by suitable screws 21 which are preferably disposed in vertical slots with which the hinges are formed, so that the position of the frame above the press may be vertically adjusted. Moreover, in order that the frame may be level with respect to the press 18 and to the plate 11 thereon, the frame legs 1'7 are provided with screw-threaded bores to receive studs 21 having resilient feet 22 thereon, such studs being secured in a predetermined position in the screwthreaded bores by suitable lock nuts 23, as is best shown in Figure 3.

A plurality of horizontal carrying members in the form of round bars 24 are provided in spaced parallel relation in the frame 16, the end portions of these bars being secured by suitable set screws 25 in suitable openings or bores with which the side members of the frame are provided, the arrangement being such that the bars may be easily removed for purposes of inspection, cleaning or replacement.

A plurality of individual supporting blocks 26 are adjustably and selectively positioned on the bars 24, the positioning and removal of the blocks on and from the bars also being facilitated by the removability of the bars from the frame, as already noted. As is best shown in Figures 4 and 5, the blocks 26 are provided with openings or bores 2'7 to slidably receive the bars 24 and are slotted as shown at 28, substantially diametrically of these openings, so that the bars 24 may be clamped therein by suitable clamping screws 29 with which the blocks are equipped. It will be apparent from the foregoing that by simply loosening the screws 29, the blocks may be slid longitudinally on the bars 24 to adjust their position thereon.

The blocks 26 are also equipped with screws 30 which serve to adjustably attach a supporting element in the form of a strap 31 to each block, so that such an element may be rotated in a horizontal plane through a full circle with respect to the associated block. The blocks and the straps 31 are formed with matching serrations 32 so that the straps are retained in a fixed position relative to the blocks when the screws 30 are tightened.

The bars 24, the blocks 26 and the straps 31 are preferably formed from non-conductive material such as hard rubber, Bakelite, etc., which does not respond toefif'ects of magnetism.

Each of the straps 31 carries at its free end an electromagnet 33 which is secured to the strap by a suitable screw 34 and extends downwardly therefrom, the wires 35, 36 of the magnet being passed through an aperture 37 in the strap 31 and provided at their free ends with plug-in type terminals 38, 39.

With particular reference to Figures 6 and 7 of the drawings, it will be noted that while the strap 31 shown in Figure 6 is straight, the strap 31a of Figure 7 is angulated so as to support the magnet 33 in an offset position with respect to the block 26. As such, the strap 31a may be used in substitution for the strap 31, when so desired. 1

A platform 41 is provided at the rear end of the frame 16, being reinforced by suitable braces 41, and supports thereon a housing 42 for certain electrical components of the invention which are used for energizing the electro-magnets 33. Such components are shown diagrammatically in Figure 9, from which it will be noted that they comprise a step-down transformer 43 having conductor means 44 for connecting the same to a suitable source of alternating current, and having its low tension secondary winding connected to a suitable rectifier 45. Low tension direct current from the latter is taken to pairs of sockets or jacks 46, 47 which are provided in the front wall of the housing and are adapted to selectively receive the aforementioned terminals 38, 39. A suitable ammeter 48 is in circuit with the rectifier 45 and the jacks, while an on-oif switch 49 is interposed in the conductor means 44 of the transformer 43. The switch 49 is preferably positioned at the front end of the frame 16 as shown so that it may be conveniently manipulated by the operator.

Finally, it will be noted that a suitable handle 50 is also provided at the front end of the frame 16, whereby the latter may be easily raised or lowered on its hinges 19.

In place of the frisketing paper conventionally used, the invention utilizes frisketing material which responds to magnetic attraction, such as for example, tempered sheet steel or shim stock, about .0015" or .002" in thickness. Pieces of such material are cut out to fit the dead metal areas 14, 15 of the plate 11, and after the plate is inked, the pieces of the frisketing material are manuually positioned on the dead metal areas, as indicated at 51 in Figure 4.

After a print from the plate is made and the plate requires to be re-inked, the frame 16 is lowered into position over the plate as shown in Figure 1 and the blocks 26 are adjusted on the bars 24 so that the electro-magnets 33 are in register with the various pieces of frisket material on the plate. Such positioning of the magnets may also require an adjustment of the straps 31' or 31a with respect to the blocks 26 as already explained, it being understood that as many magnet carrying blocks are used on the bars 24 as necessary so that each individual piece of frisket material is engaged by at least one magnet. Several of the blocks 26 may be positioned on the same bar 24 and if desired, two or more magnets may be provided for a single piece of frisket material, if the latter is of such size and/or shape that a single magnet would not be sufficient to hold the same.

In any event, after the several magnets are in register with the pieces of frisket material, the switch 49 is turned on and the terminals 38, 39 of the individual magnets are inserted in the sockets or jacks 4-6, 47, whereby the magnets become energized and positively hold the pieces of frisket material by magnetic attraction. The entire frame 16 is then raised in the direction of the arrow 20 and the pieces of frisket material, adhering to the magnets, are simultaneously lifted from the plate 11, so that the plate may be re-inked while the pieces of frisket material are out of the way.

After re-inking of the plate, the frame 16 is simply lowered to its initial position, whereby the pieces of frisket material held by the magnets are accurately redeposited on the dead metal spots of the plate from which they were lifted. The magnets are then de-energized by turning off the switch 49, so as to permit the pieces of frisket material to remain in place when the frame 16 is again raised preparatory to the making of the next print from the plate.

It will be apparent from the foregoing that the invention thus provides a highly convenient and expeditious manner for handling the several pieces of frisket material simultaneously, and thereby completely eliminates the tedious and expensive conventional procedure of removing and replacing by hand each individual piece for each individual printing.

The terminals 38, 39 and the sockets 46, 47 are preferably color coded or otherwise marked as to polarity, so that the magnets 33 may be uniformly polarized.

However, when for example two magnets are used in connection with a single piece of frisket material, it is desirable that they engage the same with opposite poles, which is effected by simply reversing the terminals 38, 39 of one of the magnets with respect to the sockets 46, 47.

It will be also noted that the wires 35, 36 of the magnets are disposed above the bars 24 so that the latter plrevent the wires from coming in contact with the inked p ate.

While in the foregoing there has been shown and described the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure,

and various modifications may be resorted to, such as may lie within the spirit and scope of the appended claims.

What is claimed as new is:

1. In the art of engraving and printing, a process for handling magnetically responsive frisketing material, comprising the steps of positioning pieces of magnetically responsive frisketing material on predetermined portions of an engraving, positioning electromagnets over the respective pieces of frisketing material in fixed relation to said engraving and attracting the pieces of frisketing material by the respective magnets, bodily removing the magnets and thepieces of frisketing material attracted thereto from the engraving to permit the latter to be inked, bodily replacing the magnets in said fixed relation to the engraving whereby the pieces of frisketing material are repositioned respectively on said predetermined portions of the engraving, deenergizing said electromagnets whereby to release thefrisketing material therefrom and permit the frisketing material to remain on said predetermined portions of the engraving, removing the deenergized electro-magnets from the engraving, and printing from the inked engraving with the pieces of frisketing material correctly positioned thereon.

2. In the art of engraving and printing, a process for handling magnetically responsive frisketing material, comprising the steps of inking an engraving, manually positioning a piece of magnetically responsive frisketing material on a predetermined portion ofsaid engraving to prevent the same from printing when a print from the engraving is made, positioning a support over said engraving in fixed relation thereto, electro-magnetically attracting said frisketing material to said support, moving the support together with the frisketing material away from the engraving to permit the latter to be linked, replacing the support over the engraving in said fixed relation thereto whereby the frisketing material is replaced on said predetermined portion of the engraving, deenergizing said electro-magnetical attraction of the frisketing material whereby to permit the latter to remain on said predetermined portion of the engraving, removing said support from the engraving, and printing from the inked engraving with said piece of frisketing material correctly positioned thereon.

3. In the art of engraving and printing, an apparatus for handling magnetically responsive frisketing material comprising a movable frame supported over an engraving in fixed relation thereto, an electro-magnet adjustably carried by said frame and adapted to attract a piece of magnetically responsive frisketing material superposed on a predetermined portion of the engraving, means for adjusting the position of said electro-magnet relative to said frame whereby to place the electro-magnet in register with the piece of frisketing material, means for energizing and de-energizing said magnet, and means for moving said frame away from and toward the engraving in said fixed relation thereto, whereby frisketing material attracted by said magnet may be replaced on said predetermined portion of the engraving.

4. In the art of engraving and printing, an apparatus for handling a piece of magnetically responsive frisketing material superposed on a predetermined portion of an engraving to prevent the same from printing when a print from the engraving is made whereby the frisketing material may be removed from the engraving to permit inking of the latter and subsequently replaced on said predetermined portion of the engraving, said apparatus comprising a frame movably supported in fixed relation over the engraving, an electro-magnet adjustably carried by said frame, means for adjusting the position of said electro-magnet relative to said frame whereby to place the electromagnet in register with said frisketing material to attract the same, means for energizing and de-energizing said electro-magnet, and means for moving said frame away from and toward said engraving in said fixed relation thereto.

5. In the art of engraving and printing, an apparatus for handling pieces of magnetically responsive frisketing material superposed on predetermined portions of an engraving to prevent the same from printing when a print from the engraving is made whereby the frisketing material may be removed from the engraving to permit inking of the latter and subsequently replaced on the respective predetermined portions of the engraving, said apparatus comprising a frame movably supported in fixed relation over the engraving, a plurality of electro-magnets adjustably carried by said frame, means for adjusting the position of said electro-magnets relative to said frame whereby to place the electro-magnets in register with the respective pieces of frisketing material to attract the same, means for energizing and de-energizing said electro-magnets, and means for moving said frame away from and toward said engraving in said fixed relation thereto.

6. An apparatus for handling frisketing material, comprising a frame adapted to be positioned over an engraving having magnetically responsive frisketing material superposed on predetermined portions thereof, said frame including a plurality of spaced carrier members, an electro-magnet, a supporting block for said electro-magnet selectively and adjustably positioned on said carrier members whereby the electro-magnet may be placed in register with the frisketing material for attracting the same thereto, means for energizing and de-energizing said electro-magnet, and means for movably supporting said frame in a fixed position relative to the engraving.

7. The apparatus as defined in claim 6 wherein said last mentioned means include a hinge swingably securing said frame to a support of said engraving.

8. The apparatus as defined in claim 6 together with a supporting element adjustably attached to said block and having said electro-magnet attached thereto, whereby the position of the electro-magnet relative to the block may be adjusted.

9. The apparatus as defined in claim 6 wherein said block is provided with an opening to selectively and slidably receive said carrier members, and means provided on said block for clamping a carrier member in said opening.

10. An apparatus as defined in claim 6, wherein the last mentioned means includes a hinge swingably securing the frame to a printing press.

References Cited in the file of this patent UNITED STATES PATENTS 2,223,357 Nahmens Dec. 3, 1940 2,234,535 Tilson Mar. 11, 1941 2,237,734 Grimsted Apr. 8, 1941 2,788,743 Schwerin Apr. 16, 1957 FOREIGN PATENTS 691,514 France May 15, 1930 

